Question 245847
Expand (4x+1)^2 = 16x^2 + 8x + 1

Substutie the above in the original equation:  

16x^2 + 8x + 1 = 3x + 4

Collecting terms:

16x^2 + 8x - 3x + 1 - 4 = 0
16x^2 + 5x - 3 = 0

It only remains to substitute a=16, b=8 and c = -3 in the quadratic formula to get the solutions.